1. Technical Field
The present invention relates to a liquid ejecting head for ejecting a liquid from a nozzle orifice, a liquid ejecting apparatus, a piezoelectric element, an ultrasonic transducer, and an ultrasonic device.
2. Related Art
Piezoelectric elements that are applied to liquid ejecting heads or ultrasonic transducers each include a diaphragm disposed on a substrate, a first electrode disposed on the diaphragm, a piezoelectric layer made of a piezoelectric material having an electromechanical conversion function, such as a crystallized dielectric material, disposed on the first electrode, and a second electrode disposed on the piezoelectric layer.
Some of such piezoelectric elements have a zirconium oxide (ZrO2) layer as a part of the diaphragm. A method of forming the zirconium oxide layer included in a diaphragm by forming a zirconium layer by a gas-phase method such as sputtering and then thermally oxidizing the zirconium layer has been proposed (see, for example, JP-A-2005-176433).
However, the zirconium oxide layer formed by the gas-phase method has low adhesion with the film as its backing or with the film formed on the zirconium oxide layer, resulting in a reduction in reliability.
In addition, there is a risk of diffusion of components contained in a piezoelectric layer into a diaphragm and backing of the diaphragm to reduce the stiffness of the diaphragm and the backing.
Such a problem occurs not only in piezoelectric elements of ink jet recording heads and ultrasonic transducers but also in piezoelectric elements of other devices.